Fuse construction



May 4 1937 H. K. WATSON Re. 20,354

FUSE CONSTRUCTION original Filed oct. e, 1952 2 sneetssheet 1 nventorsMay 4, 1937. H. K. WATSON Re 20,354

v FUSE CONSTRUCTION Original Filed Oct. 6, 1952 2 Sheets-Sheet 2 GttomegReiuued May 4, 1937 UNITED STATES PATENT oFFlcE Line Material Company,

South Milwaukee,

Wis., a corporation of Delaware original No. 1,987,039, ama January s',1935,

semi No. 636,434, omver s,- 1932. Application for reissue July 13, 1936,Serial No. 90,393

20 Claims.

This invention relates to fuse constructions, and is particularlydirected to a housed expulsion fuse type.

Objects of this invention are to provide a novel form of housed fuse inwhich a body portion is provided with stationary contacts held in placein a novel manner by means of the cooperation of a locking plate with anundercut hole so that cementing of the bolts, screws or other projectingmembers within the porcelain is'not necessary, and so that it is notnecessary to have any exposed bolts or screws extending through theporcelain which'thereafter have to be cemented up or covered at theirouter ends.

In greater detail, objects of this invention are to provide a novelconstruction whereby the stationary contacts may be secured eitherrigidly within vthe body portion or may be held in a floating manner sothat even Wide variations may be cared for in an automatic manner, thestationary contacts including the terminal members and a locking platefreely iioating as a unit without in any way sacrificing the security ofthe electrical contact between the fuse mechanism carried by the doorand the stationary contacts carried bythe -body portion.

Further objects are to provide a novel form 'of latching arrangement fortemporarily latching the fuse cartridge to the door which cooperates orinterlocks with the stationary contacts, thereby aiording at one and thesame time means for temporarily locking the door closed, while at thesame time insuring a binding action upon the fuse terminals 'and againstthe stationary contacts, so that a good electrical contact isautomatically insured by the mere closing of thel door.

Further objects are to provide brush contacts which are carried by thestationary contacts and which engage contact portions carried by thei'use cartridge, one of said contact-portions. carrled by the fusecartridge also servingv as a lock for the free end oi' the expulsionlink fuse. v

Further objects are to provide a novel means of locking the free end ofthe expulsion fuse link in place and to provide such a construction thatit may be simply made, that it inherently tends to lock the free end ofthe fuse, and that this locking action is augmented by the cooperationof the adjacent brush contacts.

More speciiically, the object speciiied in the `foregoing paragraph isto provide for fuse cartridges having an open lower end, a springactuated fuse link clamping or locking lever mounted on the cartridgeand clampingly engaging4 the (ci 20c-13s) end of a fuse link projectingfrom the open' lower end of said tube. 1 l

A still further object is to provide for fuse cartridges having an openlower encil and 'a fuse link projecting therefrom, a spring actuatedclamping or locking lever pivotally associated with the cartridge, thelever clampingly engaging the link and serving as a conductor connectingthe link with a line terminal.

Embodiments of the invention are shown in the accompanying drawings, inwhich:

Figure lfis a vertical sectional view through the body portion and doorshowing the i'use cartridge in place.

Figure 2 is a transverse sectional View on the line 2-2 of Figure 1.

Figure 3 is an enlarged sectional view on the line 3-'3 of Figure 1.

Figure 4 is a fragmentary view showing a detail of the locking means.

Figure 5 is a view of a modied form of locking means showing a oatingtype of terminal.

Referring to the drawings, it will be seen that the fuse. cutoutcomprises a body portion I formed of porcelain or other suitablematerial and provided with a hinged door 2, also formed of insulatingmaterial. This hinged door is provided with an aperture 3 adjacent itslower end into which or through which the end of the .fuse tube orcartridge 4 projects.

'I'his cartridge is provided with an upper terminal member 5 equippedwith a cap nut 6 by means oi which the upper end of the fuse link may beheld clamped to the upper contact in the usual manner. The fuse link 1extends outwardly through the bottom end of the-fuse tube v 4 and isheld in binding engagement with a saddle-like clip 8 clamped 'about thelower portion of the fuse tube 4 by means of a bolt 9, as shown inFigure 3. It is to be noted that this saddlelike member has two inwardlyturned lips I which carry a pintle pin I I, see particularly Figures 1and 3. The pintle pin pivotally supports a fuse link locking lever orlocking member I2, which is formed preferably of sheet metal, as shownmost clearly in Figure 1. This member I2 is provided with an inwardlyturned portion I3 whose inner end abuts the main body portion of themember I2 and forms with the body portion a somewhat elongated loop. Apair of iingers Il, see Figure 1, are inwardly turned to hold the leverI2 in contact with the pintle pin II .at the inner end oi'- the loopformed in the member I2, as most clearly shown in Figure 1.

Further, it will be noted that the portion I saddle-like clip 8 and thefuse tube 4.

of the member I2 provides somewhat'of a cam face which locks or bindsagainst the free endof the fuse link 1 and holds such fuse link tightlyin contact with itself and with the adjacent face of the clip 8. It ispreferably. to hold a small leaf spring I6. see Figure 1, clampedbetween the This leaf spring I6 has a projecting tongue I1 which passesthrough an aperture I8 formed in the intumed end I8 of the clampinglever I2. It is preferable to provide a small outwardly turned end I6'on the leaf spring. see Figures 1 and 3, which hooks back of thesaddle-like clamp or fitting 8.

The leaf spring I6 therefore, urges the clamping lever I2 into bindingengagement with the fuse link, as sho'wn in Figure 1. However, it may bereleased from the fuse link by merely rocking the lever I2 away from thefuse tube. This construction, therefore, provides a very simple meanslfor releasably attaching the free end of the fuse link to the lowerterminal or contact member of the fuse.

'I'he body portion carries a lower terminal member or contact member 20and an upper terminal member or contact member 2|. These members areprovided with brush contacts 22 and 23 respectively to engage the lowerand upper contacts or terminal members of the, fuse cartridge or fusetube. 'Ihe lower brush member 22 binds against the lever I2 when thecover is in closed position, as shown in Figure 1, and thus cooperateswith the lever I2 to securely clamp the free end of the fuse link inplace.

. Each of the terminal members is provided with any suitable means toreceive the ends of the conductors leading to the fuse structure. Forinstance, each may belprovided with an aperture 24 to receive the endo'f the conductor and a Set screw 25 to clamp such end.

The body portion I is provided with an undercut drilled hole or anundercut cast hole adjacent each of the terminal members 2l) and 2|, as

may be seen from reference to Figures 1, 2, 4 and 5. These holes areidentical in construction and each comprises preferably a generallyrectangular, transversely elongated opening 2B, which is provided withan undercut 21, thereby leaving an overhanging shoulder 28 on each sideof the elongated opening 26. Figures 1 and 5 show this construction veryclearly.

'I'he terminal members 20 and 2I are each provided with a transverselyelongated spacer 28 which ts within the transversely elongated hole 26.A locking plate 30 is located in the undercut portion or cutout 21 andis held to the member 29 by means of a pair of screws 3|.

It is obvious that the locking plates 3U may be turned transversely andslipped through the elongated hole 26 and thereafter may be turnedcrossways oi' the holes 26, so that they engage theshoulders 28 of theundercut, see Figure 1. Thereafter the screws are tightened, thuslocking the terminalmembers 2II and 2| securely in. place.

If the boss or spacing member 29 is made slightly short, as shown inFigure 1, a true clamping action occurs and the terminal members areheld rigidly in place. However, it is sometimes desirable to' provide afree floating terminal member either at the upper or lower terminalmember or at both places to take care of inaccuracies that may occur inthe manufacture of the device.

To secure this free oating action, the terminal member, such forinstance as indicated at 22 in ss or spacer overhanging Figure 5, may beprovided with, 33 which is slightly longer than he wall above or\infront of the undercut 21.l In

this case the locking plate or elongated nut 3l doesnot engage theshoulders 2l and thus a slight adjustment is permitted, thereby securingfree floating for the terminal members, while in no way interfering withtheir secure electrical contact with the contacts of the fuse clip ortheir secure attachment to the incoming conductors. A

It is also a feature of this invention to provide a novel .form oflatchlng means for latching the fuse to the door. For example as shownin Figures 1 and 2, the door is provided with a pair of spring latchingarms or movable contact arms 34 between which the upper contact 5 oi thefuse is positioned. These spring arms are preferably provided withslightly indented portions or nibs v 35 which ilt within recesses 36formed in the contact 5 and thus tend to lock the fuse in place evenwhen the door is open.

The U-shaped spring arms 34 are provided with outwardly turned orrounded end portions 31 which are received between the stationarycontact arms or spring arms 38 of the upper terminal member, asindicated in Figures 1 and 2. It is preferable to provide the springarms 38 with inwardly turned or inwardly rounded portions Il Aso that atrue interlocking action occurs, as shown in Figure 2. This constructionproduces a locking action for the door in addition to securing a bindingaction between the arms 34 and the upper contact 5 of the fuse 'and alsoa binding action between the arms 34 and 38, thus securing a veryreliable electrical contact.

It is mbe noted particularly that thisminvention provides interlockingmeans which may be very simply formed of ordinary strap copper or brassor similar material. Further, it will be seen that the locking means forthe fuse link also may be formed of strap material in a very simplemanner.

An additional point which is to be particularly noted is that theterminal members are secured to the body portion by the coperation ofthe locking plate with the undercut cast or drilled holes formed in thebody portion, and thereby there are nol exposed end metal portions, suchas bolts, or screws, which have to be cemented over or otherwiseprotected in the finished product. It is, of course, obvious that thisconstruction could be followed for other types of fuse than theexpulsion fuse chosen for illustration. In other words, the manner ofsecuring the` terminal means and the provision of brush contacts couldbe followed whether an expulsion type or some other type of fuse wereused.

It will be seen further that a very simple lockingv means has beenprovided which not only locks the door closed, but also causes aninterparent that I have provided a novel fuse link clamping lever whichldirectly engages the prolecting end of the fuse link and serves as aconductor between the link and the line terminal or brush contact 22.

Although this invention has been'described in considerable detail, it isto be lunderstood that 75 such description is intended as illustrativerather than hunting, as the invention may be variously embodied and itis to be interpreted as claimed.

I claim:

i. A fuse comprising a housing, terminals mounted within said housing,one of said terminals having a contact, the other of said terminalshaving a U-shaped spring contact provided with .Y inturned portions, adoor for said housing, a fuse cartridge carried by said door, said fusecartridge having a `contact adjacent one end provided with indentations,a spring clip carried by'said door `and provided with projectionsadapted to enter the indentations of said i'use contact, said springclip having projecting ends adapted to be received between the inturnedends of the said U- shaped spring contact, said fuse cartridge having asecond contact engageable by said first mentioned contact.

2. A fuse comprising a housing, terminals mounted within said housing,one of said terminals having a contact, the other of said terminalshaving a U-shaped spring contact provided with inturned portions, a doorfor said housing, a fuse cartridge carried by said door, said fusecartridge having a contact adjacent one end provided with indentations,a spring clip carried by said door and provided with projections adaptedto enter the indentations of said fuse contact, said spring clip havingprojecting ends adapted to be received between the inturned ends of-thesaid U-shaped spring contact, said fuse cartridge having a secondcontact engageable by said first mentioned contact, said door having alower portion for engaging the lower portion of said fuse cartridge, andsaid iirst mentioned contact forcing the lower portion of said fusecartridge into engagement with the lower portion of said door.

3. A fuse comprising a fuse cartridge having a contact adjacent one endthereof, a secondcontact spaced from the other end of and embracing saidfuse cartridge, a fuse link electrically joining said contacts andthreaded through said cartridge around one end thereof with the free endof the fuse link located adjacent said second mentioned contact, and amovable clamping lever pivotally carried by said second mentionedcontact for clamping the free end of said fuse link in direct engagementwith said second contact.

4. A fuse comprising a fuse cartridge having a contact adjacent one end'thereof, a second con tion.

5. A fuse construction comprising a housing, terminals mounted withinsaid housing, one of said terminals having contact means, the other ofsaid terminals having brush contact means, a fuse cartridge comprising atube having an open end and a contact adjacent the other end thereof,said contact being engageable by said iirst mentioned contact, said fusecartridge having a contact adjacent its open end, a fuse linkelectrically joining the contacts of saidfuse cartridge and loopedoutwardly about the open end of said fuse cartridge and having a freeend adjacent the last mentioned contact'of said fuse cartridge, a leverpivotally mounted upon said last mentioned contact of said fusecartridge and having/a cam face to clamp the free end of said fuse linkagainst such contact, and a spring for urging said lever into clampingposition, said brush contact engaging said lever when said device is inoperative pontion and additionally urging said lever towards clampingposition.

6. An expulsion fuse cartridge comprising a tube having an open end, acontact carried adjacent the opposite end oi' said tube. 'a contactclampedl around said tube `adjacent the open end thereof, a fuse linkjoining said contacts and threaded through said tube and looped aroundthe open end of said tube, and having its free end adjacent`the contact'clamped about said tube, a lever pivoted to said last mentioned contactand having a cam portion for binding the free end of said fuse link tosuch contact, and a spring clamped in position by said last mentionedcontact and urging said lever to clamping position.

7.. In a fuse construction, the combination of a housing, said housinghaving spaced recesses opening into saidhousing only, terminals locatedwithin said housing, and means releasably interlocldng with said housingadjacent said recesses for holding said terminals in place.

8. In a fuse construction, the combination of a housing having spacedundercut recesses opening into said housing only, l terminals locatedadjacent said recesses, and means located within the undercut of saidrecesses for clamping said terminals in place.

i?. In a device of the class described, an insulating body portionhaving spaced undercut recesses opening through one face only of saidbody portion, terminals located adjacent said recesses, and meanslocated within the undercut of said recesses and operatively connectedto said terminals for clamping said terminals to said body portion. I

10. In a fuse construction, the combination of a housing having spaced,undercut recesses opening into said housing only, terminals locatedwithin said housing adjacent said recesses, members retained within theundercut portion of said recesses, and screws operatively connectingeach terminal with its corresponding member.

11. In a fuse construction, the combination of a housing having spacedapertures, each aperture being provided with an elongated portion and anundercut inner portion terminating in a closed end, terminals mountedwithin said housing adjacent to apertures, elongated members passablethrough the elongated portion of the apertures and adapted to be turnedtransversely thereof, and screws passing through the terminals andengaging the elongated members and locking said terminals in place.

12. In a fuse construction, the combination of a housing having spacedapertures, each aperture being provided with an elongated portion and anundercut inner portion terminating in a closed end, terminals mountedwithin said housing adjacent to apertures, elongated Vmembers passablethrough the elongated portion of the apertures and adapted to be turnedtransversely thereof, screws passing through the terminals and engagingthe elongated members and locking said terminals in place, and spacerspositioned between said elongated members and said terminals.

13. In a fuse construction, a fuse cartridge having an open end andrelatively spaced contact means mounted on said cartridge, one of saidcontact means being adjacent saidopen end, and including a pivotedlclamping lever, a fuse llnkin said cartridge'electrically connectingsaid contact means and having one end projecting from said open end andclamped by said lever to a portion of said one of said contact means,and spring means mounted onsaid tube and coacting between said tube andsaid lever, thereby to hold the projecting end of said link in clampedposition, said lever being movable only about a single pivotal axis. p

14. In a fuse construction, a fuse cartridge having an open end andrelatively spaced contact means mounted/thereon, and a fuse link in saidcartridge electrically connecting said contact means and projecting fromsaid open end, one of said contact means including a clamp having asingle pivotal axis and resiliently biased to clamping engagement withthe projecting end of said fuse link.

15. In a fuse construction, a fuse cartridge having an open end andrelatively' spaced contact means mounted thereon, and a fuse link insaid cartridge electrically connecting said contact means and projectingfrom said open end, one of said contact means including a clamping leverhaving a single pivotal axis and a spring urging said lever intoclamping engagement with the projecting end of said fuse link. t

1 16. In a fuse construction, a fuse cartridge closed at one end andopen at the other end and provided with a contact at its closed end, afuse link in said cartridge projecting from the open end thereof, andlink clamping means adjacent the open end of said cartridge, said meansincluding a contact member, a lever movable about a single pivotal axison said member and a spring urging said lever about its pivot intoclamping engagement with said link and contact member. A

17. In a fuse construction, a fuse cartridge closed at one end and openat the other end andtion to said contact and to the open end of saidcartridge, a clamping lever having a single pivotal axis onsaid support,and clamping means on said tube including a spring urging said leverinto clamping relation to said means, and a fuse link in said cartridgehaving one end projecting from the open end of the cartridge and clampedbetween said lever and means.

18. In a fuse construction, an insulating sup'- port having a pair ofrelatively spaced terminal Y members, a fuse cartridge having contactmembers engaging said terminal members, and a fuse link electricallyconnecting said contact members, one of said contact members including aclamping lever engaging said link and one of said terminal members,thereby serving as a conducting member between said link andlast-mentioned terminal member.

19. In a i'use construction, an insulating sup-J lever pivotallyconnected with said tube, the projecting end of said link being inclamped and electrical contact with said lever and the lever being incontact with one oi' said terminal members, whereby the lever serves asconducting means between the fuse link and last-mentioned terminalmember.

20. In al fuse construction, a fuse cartridge having an open end andrelatively spaced Contact means mounted thereon,.one of said contactmeans comprising arelatively rigid member secured tosaid tube and aclamping lever pivotally connected at one end with said relatively rigidmember, co-acting clamping means on said member and said lever, and aspring mounted onsaid tube and urging the free end of said clampinglever about said pivot.

HIRAM K. WATSON.

